A glance at Moscow's contested mayoral race

MOSCOW (AP) — Moscow is preparing for its first mayoral election in a decade. Though an incumbent backed by Vladimir Putin is expected to win handily, the entry of a charismatic opposition figure into the race is changing Russian politics in ways that could pose a challenge to the president's power in the years ahead. As Alexei Navalny holds his last rally in rain-soaked Moscow on Friday, here is a look at what could be a pivotal election.

WHY DOES SUNDAY'S VOTE MATTER?

Navalny has brought grassroots politics to the Russian capital for the first time, inspiring thousands of enthusiastic volunteers to join his campaign. Sunday's election is the first since 2003 and the first since the Kremlin last year reversed Putin's 2004 decree abolishing direct elections for the Moscow mayor and other regional leaders.

If Navalny can get more than 20 percent and even come close to forcing incumbent Sergei Sobyanin into a run-off, it could embolden the opposition in its efforts to one day drive Putin from power. A vote seen as unfair could trigger protests against the government.

WHO IS NAVALNY?

Navalny started an anti-corruption blog in 2009, and used his status as a minority stakeholder in state-owned companies to expose corruption, most famously uncovering a $4 billion theft by oil pipeline operator Transneft. His charisma and cutting wit turned him into an online folk hero of the opposition, and he soon began taking a stance on broader political issues, coining the nickname for Kremlin-backed United Russia as the "party of crooks and thieves."

When unprecedented protests broke out after 2011 parliamentary elections that independent observers said were rigged, Navalny cemented his status as de facto leader of the opposition, leading street marches that attracted tens of thousands of people from across the political spectrum.

WHY IS THE KREMLIN LETTING HIM RUN?

Navalny was sentenced in July to five years in prison for embezzlement in a case that he and his supporters describe as legally dubious and punishment for his exposure of high-level corruption. He left the courtroom in handcuffs, but a day later in a surprise turnaround, prosecutors requested he be set free until his appeal could be heard.

Most have speculated that it was Sobyanin who had Navalny set free, in order to ensure that the election would look as fair as possible and legitimize the Kremlin candidate as a politician.

WHO IS SOBYANIN?

Sobyanin started his political career in the oil-rich Siberian town of Tyumen, but quickly moved up the political hierarchy to work as an aide in the Kremlin. He was parachuted into the seat of Moscow mayor in 2010 after Yuri Luzhkov, who governed the city for almost two decades, was forced out.

Sobyanin is most popular among the elderly who rely on his office for their pensions, but he has gained respect among the middle class for directing some of the city's $54 billion budget toward its parks and cultural institutions. Sobyanin has relied on his financial advantage and political backing to run his campaign for him, and has mostly played the regal and removed incumbent, refusing to participate in debates and appearing only rarely in stage-crafted public events.

HAS THE CAMPAIGN BEEN FAIR?

Navalny himself has characterized the elections as "competitive, but not fair." While he has been allowed to run, he has been targeted by an increasingly dirty campaign. Putin has smeared him as corrupt, and election officials have accused him of being funded from abroad, while Kremlin-friendly news organizations have released grainy video footage purporting to show his campaign manager at a strip club.

AND THE VOTE?

Sobyanin is doing everything to make sure that it will be fair or at least look that way. The incumbent has even cozied up to Golos, an independent election monitor that has come under immense official pressure, to ensure that the voting goes smoothly, approving its proposal to install cameras in polling stations.

Golos deputy chairman Grigory Melkonyants said this may be enough to stop overt ballot-stuffing but it won't ensure a clean victory. "You might observe some extra people showing up on the voter registration list on election day," he said, referring to the dead souls who often crowd the list of voters at Russian polling stations.

He suggested that the Kremlin is playing a risky game by allowing Navalny to run. "If Sobyanin gets 51 percent, everyone will have a lot of doubts about the results," Melkonyants said. "Essentially, if there's not going to be a second round, then the first round has to be an uncontestable victory, more than 60 percent."

DOES NAVALNY STAND A CHANCE?

With 102 million rubles ($3.1 million) in campaign funds from over 16,000 donors, around 20,000 volunteers have hit the campaign trail for Navalny, passing out leaflets in the metro or hanging banners on balconies.

But despite this unprecedented effort, it's unlikely that Navalny will win. A week before the election, a poll by the independent Levada Center predicted that he would get 18 percent of the vote compared to 58 percent for Sobyanin — a significant rise from the 6 percent Navalny was polling in July, but not enough to get Sobyanin under the 50 percent mark that would force him to a run-off. The Levada poll has a margin of error of 3.4 percentage points.

For Navalny, a strong showing could lead to a shortening of his prison sentence if the Kremlin feels that this would help diffuse discontent.